1. Field of the Invention
The present invention relates to a sensor arrangement for an active member, especially such as a landmine which is deployed against ground and airborne target objects, including a waking or proximity sensor which is responsive to the approach of a target object.
2. Discussion of the Prior Art
The mines of a modern, intelligent blocking system are essentially designed to be equipped with sensor arrangements, which in order to enable an effective combatting of a potential target object penetrating into the blocked area, must be capable of detecting, locate and, possibly, also classifying this target object. Hereby, the target object should be acquired even while still at a distance of a few hundred meters, when due to the presence of artificial or natural obstructions, there is not afforded a direct ( optical ) line of sight between the sensor arrangement and the target object. This can be basically carried out by means of a so-called "None Line of Sight" radar which operates at such low frequencies that these, as a consequence of diffraction phenomena encountered at roughnesses, extensively evidence a wave dispersion along the ground and thereby beyond the optical shadow boundary; and correspondingly also feedback signals from covered reflectors to the transmitting-receiving or transceiver installation. In order to be able to more readily recognize the penetration of potential target objects into the surveilled blocked area, even when no approach of a target object is signaled by a waking or proximity sensor; from time to time there is activated the high-frequency energy radiation, in order to determine and to store the surrounding terrain situation (with its locally-required, at least quasi-stationarily present and natural reflectors); inasmuch as through a comparison with the thus obtained information over the terrain, there can be more easily recognized the penetration of a foreign body and thereby of a potential target object. The evaluation in the amplitude of the reflected receiving energy facilitates a certain degree of target classification. By means of an evaluation of the reflection within so-called time frames; in effect, in dependence upon distance, there is also obtained a multiple-target resolution.